Trial Outcomes & Findings for Evaluating the Safety and Efficacy of Oral Lenvatinib in Medullary and Iodine-131 Refractory, Unresectable Differentiated Thyroid Cancers, Stratified by Histology (NCT NCT00784303)

162 participants were screened for entry into the study, from which 45 were screening failures and 117 entered into the study and were treated.

Evaluating the Safety and Efficacy of Oral Lenvatinib in Medullary and Iodine-131 Refractory, Unresectable Differentiated Thyroid Cancers, Stratified by Histology

ORR was the percentage of participants with best overall response (BOR) of complete response (CR) and partial response (PR) based on modified Response Evaluation Criteria in Solid Tumors (RECIST) 1.0 for target lesions using magnetic resonance imaging/computed tomography (MRI/CT) scans, as determined by independent imaging review (IIR). CR was defined as disappearance of all target lesions. PR was defined as at least a 30% decrease in the sum of the longest diameter of target lesions, taking as reference the baseline sum of the longest diameter. ORR=CR+PR, was presented with 2-sided 95% confidence interval (CI) by the method of Clopper and Pearson.

Up to 9 samples per participant were obtained at specific time points. Plasma concentrations of lenvatinib were analyzed using standard analysis methods. Due to the sparse PK sampling in this study, the data were pooled with data from other Phase 1 studies conducted in participants with solid tumors for PK model development and covariate analysis. Individual exposure (steady state AUC) to lenvatinib in MTC and DTC subjects in this study was derived based on the individual predicted steady state AUC from the final PK model. Only data for participants taking 24 mg lenvatinib daily were reported (participants taking 20 mg lenvatinib daily were not included in this data set).

Blood samples to measure free T4 were collected at Screening (Baseline), Cycle 1 Day 15 (MTC cohort), Day 1 of Cycles 2 to 20, and Final Visit. Changes in free T4 concentration values from baseline to specific time points were calculated. Only participants with both baseline and relevant visit values were included.

Blood samples to measure free TSH were collected at Screening (Baseline), Cycle 1 Day 15 (MTC cohort), Day 1 of Cycles 2 to 20, and Final Visit. Changes in free TSH concentration values from baseline to specific time points were calculated. Only participants with both baseline and relevant visit values were included. For any free TSH result that was reported as \<0.008 mIU/L, 0.004 mIU/L was used for calculating summary statistics.

Blood samples to obtain serum were collected at Cycle 1 Day 1 (Baseline), Day 1 of Cycles 2 to 19, Final Visit, and were analyzed for thyroglobulin concentration. Percent changes in thyroglobulin concentration values from baseline to specific time points were calculated. Only participants with both baseline and relevant visit values were included.

Blood samples to obtain serum were collected at Cycle 1 Day 1(Baseline), Day 1 of Cycles 2 to 20, Final Visit, and were analyzed for calcitonin concentration. Percent changes in calcitonin concentration values from baseline to specific time points were calculated. Only participants with both baseline and relevant visit values were included.

Blood samples were collected at Cycle 1 Day 1(Baseline), Day 1 of Cycles 2 to 20, Final Visit, and were analyzed for CEA concentration. Percent changes in CEA concentration values from baseline to specific time points were calculated. Only participants with both baseline and relevant visit values were included.

Blood samples to obtain serum were collected at Cycle 1 Day 1(Baseline), Cycle 1 Day 8, Cycle 2 Days 1,8 \&15, Cycles 3 to 9,11,13 Day 1, Final Visit, and analyzed for CytoC concentration. Changes in CytoC concentration values from baseline to specific time points were calculated. Only participants with both baseline and relevant visit values were included. For results reported as below quantifiable level (BQL), zero was used for calculating summary statistics. If more than 50% of the results at a visit were BQL, then only 'n', 'minimum' and 'maximum' were calculated for summary statistics.

Blood samples to obtain serum were collected at Cycle 1 Day 1(Baseline), Cycle 1 Day 8, Cycle 2 Days 1,8 \&15, Cycles 3 to 9,11,13 Day 1, Final Visit, and analyzed for M-30 concentration. Changes in M-30 concentration values from baseline to specific time points were calculated. Only participants with both baseline and relevant visit values were included. For results reported as BQL, zero was used for calculating summary statistics. If more than 50% of the results at a visit were BQL, then only 'n', 'minimum' and 'maximum' were calculated for summary statistics.

Blood samples to obtain serum were collected at Cycle 1 Day 1 (Baseline), Cycle 1 Day 8, Cycle 2 Days 1, 8, and 15, Cycles 3 to 9, 11, 13 (Day 1), Final Visit, and analyzed for Casp 3/7 concentration. Changes in Casp 3/7 concentration values from baseline to specific time points were calculated. Only participants with both baseline and relevant visit values were included. The concentrations of Casp 3/7 were BQL for most participants at most time points. For results reported as BQL, zero was used for calculating summary statistics. If more than 50% of the results at a visit were BQL, then only 'n', 'minimum' and 'maximum' were calculated for summary statistics.

DoR was based on IIR was the time from date of the first CR or PR until the date of first documentation of disease progression or date of death, if death occurred prior to disease progression, for the participants who had BOR of CR or PR. Participants without progressive disease or death were censored at the date of last adequate tumor assessment. Duration of response = End Date - Date of first CR or PR + 1

DCR was the percentage of the participants who had BOR of CR, PR, and stable disease (SD) with the minimum duration of SD lasting greater than or equal to 7 weeks, based on assessments by IIR. DCR = CR+PR+SD greater than or equal to 7 weeks

CBR was the percentage of the participants who had BOR of CR, PR, and SD with the minimum duration of SD lasting greater than or equal to 23 weeks, based on assessments by IIR. CBR = CR+PR+SD greater than or equal to 23 weeks

TTR was defined as "time from start of treatment to the time when a participant first achieves a response of PR/CR" based on assessments by IIR. TTR was only calculated for participants with confirmed PR or CR.

PFS was defined as the time from the date of treatment start until progressive disease or death from any cause in the absence of progressive disease. Disease progression was defined as at least a 20% increase in the sum of the longest diameter of target lesions (taking as reference the smallest sum on study), recorded since the treatment started or the appearance of 1 or more new lesions as assessed by IIR using RECIST 1.0. The duration of PFS was calculated as end date minus date of first drug plus 1, based on assessments by IIR. PFS was calculated using Kaplan-Meier estimate and presented with 2-sided 95% Cl.

OS was defined as the time from the date of treatment start until death from any cause. The duration of OS was calculated as 'end date minus date of first drug plus 1', based on assessments by IIR. Participants without a reported death or those lost to follow-up were censored at their last known alive date at the database cutoff. OS was calculated using Kaplan-Meier estimate and presented with 2-sided 95% Cl.

Safety assessments consisted of monitoring and recording all AEs (serious and non-serious) and SAEs; concomitant medications, regular monitoring of hematology, blood chemistry, and urine values; periodic measurement of vital signs, Eastern Cooperative Oncology Group (ECOG) performance status, New York Heart Association (NYHA) assessments, electrocardiograms (ECGs), echocardiograms; and performance of physical examinations.